pros:
If an access swich/switch port failed then AP still forward traffic through other switch once power restored through other port.
when PoE failed on its connected switch, it may still work via other port.
Having two ethernet port on AP may require to talk to different switches/stack to achieve AP port redundancy through lag or stateful switch over when cable/switch/AP port failure.
if one physical port become bad on AP, it can be still used with other.
(However, AP/physical port failure can be takencare at RF level using self healing.)
cons:
require additional switch and its config maintanece
currently, AP doesn't require 2 physical port for data transfer perspective.
Require x2 PoE ports.
Additional port increases the cost on AP.
it is possible cisco may make it in future.
